1. Field of the Disclosure
The present disclosure relates to an apparatus for auxiliary contact of a circuit breaker, and more particularly, to an apparatus for auxiliary contact of a circuit breaker, which can improve the reliability in displaying, to the outside, a normal or overcurrent state of the circuit breaker through the apparatus, reduce the manufacturing cost of the apparatus and simplify the entire structure of the apparatus by reducing the number of components used in the apparatus, and prevent components from being easily broken in the use of the apparatus.
2. Description of the Conventional Art
In general, a circuit breaker refers to a device for opening/closing a load or interrupting current when there occurs an accident such as earthing or short circuit in a transmission & sub-station system or an electrical circuit. Also, a circuit breaker, in which a circuit breaking part is insulated by an insulator and assembled, may generally manually open or close a line in use or may open or close the line from a remote area through an electrical manipulator, or the like, outside a metal container. Also, when there occurs an overload or short-circuit, the circuit breaker automatically cuts off the line to protect an electric power system and a load device.
In a circuit breaker as described above, a fixed contactor and a movable contactor are installed in a circuit breaking part. The fixed contactor and the movable contactor are contacted with each other to allow current to flow therethrough. In addition, when a large current flows due to a defect of the circuit breaker, the movable contactor is rapidly separated from the fixed contactor, thereby interrupting current.
Meanwhile, a circuit breaker may be classified into an air operation method, a hydraulic operating method, a spring operation method, and the like according to the way in which a circuit breaking part is operated. A circuit breaker may also be classified into an air circuit breaker (ACB) that extinguishes arc by blowing air, a gas circuit breaker (GCB) that extinguishes arc by blowing gas, and the like, according to the way in which arc generated when a movable contactor is separated from a fixed contactor by manipulating a circuit breaking part is extinguished.
In a circuit breaker as described above, a separate apparatus for auxiliary contact is generally installed in a circuit breaking part. The apparatus refers to an apparatus that transmits signals to the outside according to opening/closing of a circuit breaking part, i.e., connection and interruption between a fixed contactor and a movable contactor.
Meanwhile, FIG. 1 is a configuration view showing a conventional apparatus for auxiliary contact of a circuit breaker. FIG. 2 is a configuration view showing a state in which a state of the apparatus when the circuit breaker is in a normal state. FIG. 3 is a configuration view showing a state in which the apparatus is pressurized as an overcurrent is applied to the circuit breaker.
As shown in FIGS. 1 to 3, components of the apparatus are provided inside a frame 10. The apparatus is configured to include a fixed contactor 12, a screw portion 11 fixing the fixed contactor 12, a movable contactor 13 contacted with or separated from the fixed contactor 12, a crossbar 14 moving upward the movable contactor 13, the crossbar 14 having a spring 16 provided therein, a lever 15 formed under the crossbar 14.
According to the configuration described above, if an overcurrent is applied to the circuit breaker, the movable contactor 13 is contacted with or separated from the fixed contactor 12 as the lever 15 and the crossbar 14 move upward, thereby displaying a state of the circuit breaker to the outside.
However, in the conventional apparatus, the movable contactor 13 is provided inside the frame 10 in a state in which the movable contactor 13 is bent to a predetermined angle. Hence, when the movable contactor 13 returns to the original position in the state in which the movable contactor 13 moves upward through the crossbar 14, a restoring force corresponding to bending of the movable contactor 13 through the crossbar 14, in addition to self-bending of the movable contactor 13, has influence on the movable contactor 13. As such, there exist many factors having influence on contact or separation between the movable contactor 13 and the fixed contactor 12. Therefore, if the conventional apparatus is used for a long time, operational characteristics of the apparatus are changed, and as a result, a malfunction of the apparatus frequently occurs.
Also, the crossbar 14 and the lever 15 which move upward the movable contactor 13 are not formed as one component but separately formed, and hence the number of components is increased. Therefore, the manufacturing cost of the apparatus is increased, and the structure of the apparatus is complicated.
Also, a separate crossbar 14 should be manufactured and used according to the structure of the movable contactor 13 and the fixed contactor 12.